The present invention relates to a power source device including a plurality of batteries connected in series, the power source device mounted for example on a hybrid vehicle capable of traveling by a driving force from an internal-combustion engine or a motor, or an electric vehicle.
A hybrid vehicle traveling by a driving force from an internal-combustion engine or a motor, or an electric vehicle traveling by a driving force from a motor includes a power source device for storing and releasing electric energy. The power source device includes a battery assembly composed of a plurality of batteries. The batteries are connected in series to obtain a desired voltage. For example, a nickel metal hydride (NiMH) battery is used as such a battery.
The power source device connects, by using a connecting member, the positive electrode of one battery of a pair of batteries adjacent to each other out of a plurality of batteries and the negative electrode of the other battery of the pair of batteries to connect a plurality of batteries of a battery assembly in series. This configuration makes it necessary to assemble a plurality of connecting members to a battery assembly thus making cumbersome the assembly work of a power source device. This is more eminent by an increase in the number of batteries constituting a power source device. This configuration may be a hindrance to a compact, lightweight and simple design of a power source device.
In order to solve such problems, various types of power source devices have been used (for example, refer to Patent Reference 1). This type of power source device includes a battery assembly composed of a plurality of batteries, a plurality of bus bars as connecting members for connecting the batteries in series, and a plate on which the plurality of bus bars are attached and which is mounted on the battery assembly. On one surface of the battery body of a battery are arranged a positive electrode and a negative electrode. On the perimeter surface of the positive and negative electrodes is formed a screw groove. The plate has a planar shape formed into an almost flat rectangular plate. The bus bar and the plate respectively include a plurality of holes used to route a positive electrode and a negative electrode.
To assemble such a power source device, a plurality of batteries are arranged side by side so that the positive electrode of a battery will be adjacent to the negative electrode of a separate battery. Next, a plate including a plurality of bus bars in a predetermined position is laid on the batteries. The positive and negative electrodes of the batteries are routed through the plate holes and bus bar holes to connect the plate and the bus bars to the battery assembly. Finally, nuts are screwed into the electrodes where screw grooves are formed to fix the connection of the battery assembly and the plate as well as bus bars. This connects the batteries in series by way of a plurality of bus bars.
With the power source device of the above configuration, a plurality of bus bars are attached to a plate before the plate is mounted on the battery assembly. Thus, connection of the battery assembly and the plate as well as the plurality of bus bars is complete when the positive and negative electrodes of the batteries are simultaneously routed through the plurality of holes in the plate and the holes for the plurality of bus bars attached to the plate and are screwed. This has simplified the assembly work in connecting a plurality of batteries of a battery assembly in series.
[Patent Reference 1] JP-A-2004-95381
With the power source device described in Patent Reference 1, the positive and negative electrodes of the batteries are simultaneously routed through the plurality of holes in the plate and the holes for the plurality of bus bars attached to the plate before the plate is mounted on the battery assembly. The electrodes slide on the inner surfaces of the plate holes and bus bar holes to cause friction, which makes it difficult to assemble a plate to a battery assembly thus placing a load on the worker. When the number of batteries, that is, the number of electrodes in a battery assembly is increased for multi-pole configuration to raise the voltage of the power source device, the load on the worker increases.